Drug design is an splendid inventive process of new medication on the basis of biological target. It is also known as rational drug design or rational design. That is the invention in medical history in order to yield significant therapeutic response. The drug is an organic molecule, when it is bind to target site it can either inhibit or activate the function of a biomolecule which results in therapeutic benefit. The drug design involves the design of such molecules that are similar to the bio molecular target site in shape and charge in order to bind to it. Drug design relies on the knowledge of the three dimensional structure of bimolecular targets.